Prevention of face-plugging on aftertreatment devices in exhaust

ABSTRACT

An inlet face for an aftertreatment device that prevents and/or eliminates face-plugging for a passageway where the inlet face is disposed. The inlet face includes a particular end surface disposed on an outer surface at the end of a substrate. The end surface includes at least one of a three-dimensional topographical configuration disposed at the end of the substrate, a chemical coating applied on the end of the substrate, or both a three-dimensional topographical configuration disposed on the end of the substrate and a chemical coating applied on the three-dimensional topographical configuration. As one example, the inlet face can be helpful in preventing carbonaceous fouling, which can result from engine exhaust material, such as carbon soot and other engine exhaust by-products.

FIELD

An inlet face is disclosed that prevents and/or eliminates face-pluggingin a fluid passageway. As one example, an inlet face is provided that isparticularly helpful for various aftertreatment devices, so as toprevent and/or eliminate carbonaceous fouling and/or the accumulation ofunburned hydrocarbons, which may be deposited on the inlet face of suchaftertreatment devices from exhaust material, such as from internalcombustion engine exhaust. An inlet face as disclosed herein can therebyprevent backpressure increase in an engine exhaust system.

BACKGROUND

Catalyzed and uncatalyzed aftertreatment devices, are well known andwidely used in various internal combustion engine applications for theaftertreatment of engine exhaust gases. For example, aftertreatmentdevices are useful for handling and/or removing exhaust materials, suchas carbon monoxide, nitric oxide, unburned hydrocarbons and soot, in theexhaust stream of an engine.

Although particulate filters are sometimes not catalyzed on the interiorsurfaces, many aftertreatment devices commonly employ a catalyzedwashcoat applied to interior surfaces within fluid passageways of acellular structure, which often resembles an interior of a honeycombstructure. Undesired exhaust material(s) react upon the catalystmaterial of the catalyzed washcoat, thus diminishing the undesiredexhaust material(s).

However, face-plugging of the fluid passageways at the inlet face ofthese aftertreatment devices continues to be an issue under certainoperating conditions. As one specific example, such problematicoperating conditions can occur when a diesel engine operates during lessaggressive duty cycles, such as but not limited to, extended idlingoperation. Frequent start and stop operation and other transientoperating conditions can also be problematic. Furthermore, face-plugginghas been known to occur at the inlet face of aftertreatment devices,such as those used in diesel engine aftertreatment applications duringcold ambient operating temperatures, or during relatively low exhausttemperature ranges, such as 220° C. to 400° C.. Such face-plugging orfouling at the inlet face has been defined as residue, such as exhaustmaterials and/or soot particles that accumulates on the outer surface ofthe cellular structure at the inlet face of an aftertreatment device,and effectively reduces the open frontal area of the aftertreatmentdevice. Face-plugging is problematic, because it can result in a sharprise in backpressure in aftertreatment or exhaust systems, which in turnmay affect engine operation and decrease system efficiency. Preventingthe formation of the soot/coke deposits during such problematicoperating conditions would be of benefit. Thus, there is a need toprovide an improved inlet face that can prevent and/or eliminateface-plugging or fouling at the inlet face aftertreatment devices.

SUMMARY

The following technical disclosure provides an improved inlet face, suchas for an inlet of an aftertreatment device. One benefit is that theimproved inlet face can prevent and/or eliminate face-plugging on theinlet of an aftertreatment device, such as by preventing and/oreliminating carbonaceous fouling and/or the accumulation of unburnedhydrocarbons which may be deposited on the inlet of an aftertreatmentdevice from exhaust material.

In one embodiment, an inlet face includes a substrate having an end witha cellular structure configured to enable fluid flow through thesubstrate. An end surface is disposed on the end of the substrate thatis configured to prevent and/or eliminate face-plugging at the end ofthe substrate and on surfaces of its cellular structure that are locatedat the end of the substrate.

In one embodiment, the inlet face includes a three-dimensionaltopographical configuration such that the outer surface of the substrateis non-planar.

In another embodiment, the inlet face includes a chemical coatingapplied on the outer surface of the cellular structure of the substrate.In one embodiment, the chemical coating is a catalytic coating.

In another embodiment, the inlet face includes both a three-dimensionaltopographical configuration and a chemical coating applied on thethree-dimensional topographical configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of one embodiment of an inlet facefor an aftertreatment device.

FIG. 2 illustrates a side sectional view of the inlet face of FIG. 1.

FIG. 3 illustrates a perspective view of another embodiment of an inletface for an aftertreatment device.

FIG. 4 illustrates a side sectional view of the inlet face of FIG. 3.

FIG. 5 illustrates a partial schematic view of one embodiment of an endsurface for an end of a substrate of an aftertreatment device andparticularly showing a side of a single cell of the end surface.

FIG. 6 illustrates a perspective view of another embodiment of an inletface for an aftertreatment device.

FIG. 7 illustrates a side sectional view of the inlet face of FIG. 6.

FIG. 8 illustrates a perspective view of another embodiment of an inletface for an aftertreatment device.

FIG. 9 illustrates a side sectional view of the inlet face of FIG. 8.

FIG. 10 illustrates a perspective view of another embodiment of an inletface for an aftertreatment device.

FIG. 11 illustrates a side sectional view of the inlet face of FIG. 10.

FIG. 12 illustrates a perspective view of yet another embodiment of aninlet face for an aftertreatment device.

FIG. 13 illustrates a side sectional view of the inlet face of FIG. 12.

FIG. 14 illustrates a perspective view of yet another embodiment of aninlet face for an aftertreatment device.

FIG. 15 illustrates a side sectional view of the inlet face of FIG. 14.

FIG. 16 illustrates a perspective view of yet another embodiment of aninlet face for an aftertreatment device.

FIG. 17 illustrates a side sectional view of the inlet face of FIG. 16.

FIG. 18 illustrates a partial elevated view of one embodiment of acellular structure for an inlet face.

FIG. 19 illustrates a partial elevated view of another embodiment of acellular structure for an inlet face.

FIG. 20 illustrates a schematic side sectional view of one embodimentfor the disposition of a chemical coating on an inlet face.

FIG. 21 illustrates a schematic perspective plan view of one embodimentfor the disposition of a chemical coating on an inlet face.

DETAILED DESCRIPTION

Generally, an inlet face is described that can prevent and/or eliminateface-plugging of a fluid passageway where the inlet face is disposed.The inlet face includes a particular outer end surface disposed at theend of a substrate. The end surface provided on the substrate canprevent and/or eliminate face-plugging on the inlet face. As oneexample, the inlet face can be helpful in preventing and/or eliminatingcarbonaceous fouling and/or the accumulation of unburned hydrocarbons onthe inlet face, which are deposited from engine exhaust material, forexample, the exhaust from an internal combustion engine.

In one embodiment, an inlet face for a fluid passageway includes asubstrate with a cellular structure configured to enable fluid flowthrough the substrate. An outer end surface configuration is disposed onthe cellular structure of the substrate and at the end of substrate. Theend surface is configured to prevent and/or eliminate face-plugging onat the end of the substrate and cellular structure. In particular, theend surface provides a configuration that can prevent, or at leastminimize, residue from being deposited on the substrate and particularlythe walls and edge surfaces of the cellular structure that are locatedat the end of the substrate. The end surface is at least one of athree-dimensional topographical configuration disposed on the end of thesubstrate, a chemical coating disposed on the end of the substrate, orboth a three-dimensional topographical configuration disposed on the endof the substrate and a chemical coating disposed on thethree-dimensional topographical configuration.

Three-Dimensional Topographical Configuration of an Inlet Face

In one embodiment, the end surface is a three-dimensional topographicalconfiguration disposed at the end of the substrate, such that the end ofthe substrate has an overall non-planar surface. That is, thethree-dimensional topographical configuration is configured such thatthe end of the substrate has a profile that does not reside in anentirely single plane.

FIGS. 1-4 and 6-17 illustrate exemplary embodiments for athree-dimensional, topographical surface configuration of an inlet face.As shown, the inlet face is particularly useful when employed forexample, on the inlet side of an aftertreatment device.

FIGS. 1 and 2 show an inlet face 10 of an aftertreatment device. Theinlet face 10 includes an outer end surface 14 provided with oneembodiment of a three-dimensional topographical configuration. As shown,the inlet face 10 is incorporated at an inlet side of a diesel oxidationcatalyst (DOC). It will be appreciated, however, that the inlet face 10shown may be suitably modified as necessary to be employed in otheraftertreatment devices. Such other aftertreatment devices include, butare not limited to, other flow-through catalytic elements like a DOC,such as a close-coupled catalyst (CCC). Other non-limiting examples ofaftertreatment devices in which the described inlet face 10 may beemployed can include an NO_(x) adsorber catalyst (NAC), a selectivecatalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), or adiesel particulate filter (DPF) or soot collector.

It will be appreciated that the inventive concepts of the inlet facesdescribed herein may be sized and dimensioned as necessary toaccommodate the inlets of such other aftertreatment devices bothmentioned and not mentioned. It further will be appreciated that theinlet face 10 may be suitably modified to be used as an outlet face onan outlet side of various aftertreatment devices, such as the outletside of any of the aftertreatment devices mentioned.

As shown in FIG. 1, the outer end surface 14 is disposed at an outer endof the substrate 12. The substrate 14 includes a cellular structure 15,resembling a honeycomb-like configuration. The cellular structure 15 isconfigured to enable fluid flow through the substrate 12 and includes aplurality of cells (details discussed below in FIG. 5). The term “fluid”is meant to be construed broadly to include any medium that can be madeto flow. As some examples only, the fluid material(s) may include, butare not limited to, any exhaust material or any material containing sootfrom a processed material. As other examples, the fluid material(s)include any material that may produce and/or leave a residue. A residueis meant to be any material that may be dried and left on the cellularstructure of the substrate, or may be a “wet” material that has been notbeen completely burned and left on the cellular structure of thesubstrate. As one example of residue is carbonaceous fouling and/or theaccumulation of unburned hydrocarbons from exhaust material, which maybe deposited on the inlet of an aftertreatment device.

The end surface 14 is disposed on an outer surface of the substrate 12at the end. As shown, the end surface 14 is a three-dimensionaltopographical configuration having a non-planar or fracturedarrangement. That is, the end surface 14 does not reside entirely in thesame overall plane, such as when viewed from its profile. (See FIG. 2.)The end surface 14 includes multiple adjacent and parallel rows 16disposed on the substrate 12. As one example only, FIG. 2 shows that theparallel rows 16 resemble v-shaped rows and may have a 90° includedangle. It will be appreciated that the v-shaped rows may be arranged atangles less than or greater than 90°, as long as the overall arrangementof the end surface 14 does not reside on entirely the same plane.

FIGS. 3-4 show another exemplary embodiment of an inlet face 30 of anaftertreatment device. The inlet face 30 provides another exemplary endsurface 34 with a three-dimensional topographical configuration. As withinlet face 10, the inlet face 30 is for a diesel oxidation catalyst(DOC). It will be appreciated, however, that the inlet face 30 shown maybe suitably modified as necessary to be employed in other aftertreatmentdevices. Such other aftertreatment devices include, but are not limitedto, other flow through aftertreatment devices like a DOC, such as aclose-coupled catalyst (CCC). Other non-limiting examples ofaftertreatment devices in which the described inlet face 30 may beemployed can include an NO_(x) adsorber catalyst (NAC), a selectivecatalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), or adiesel particulate filter (DPF) or soot collector.

It will be appreciated that the inventive concepts of the inlet facesdescribed herein may be sized and dimensioned as necessary toaccommodate the inlets of such other aftertreatment devices. It furtherwill be appreciated that the inlet face 30 may be suitably modified tobe used as an outlet face at the outlet side of various aftertreatmentdevices, for example in outlets of any of the aftertreatment devicesmentioned.

The inlet face 30 includes the end surface 34 disposed on an outer endsurface of the substrate 32 having a cellular structure 35. The cellularstructure 35 is configured to enable fluid flow through the substrate 12and includes a plurality of cells (details discussed below in FIG. 5).As with inlet 10, the term “fluid” is meant to be construed broadly toinclude any medium that can be made to flow. In some examples only, thefluid material(s) may include, but are not limited to, any exhaustmaterial or any material containing soot from a processed material. Asother examples, the fluid material(s) can include any material that mayproduce a residue that is left on the cellular surface of the substrate.

The end surface 34 is disposed on an outer surface of the substrate 32and at the end. The end surface 34 also is a three-dimensionaltopographical configuration having a non-planar or fracturedarrangement. As with surface 14, the end surface 34 does not reside inentirely the same overall plane, such as when viewed from its profile.

Differently from end surface 14, the end surface 34 includes apyramid-like configuration resulting from the intersection of parallelv-shaped rows. As shown, the end surface 34 includes a first set ofmultiple rows 36 disposed on the substrate 32. The first rows 36 areadjacent and parallel to each other and resemble v-shaped rows. As oneexample only, FIG. 4 shows that the first rows 36 may have a 90°included angle. (See FIG. 4.) It will be appreciated that the v-shapedrows may be arranged at angles less than or greater than 90°, as long asthe overall arrangement of the surface 34 does not reside in an overallsame plane.

The end surface 34 further includes a second set of multiple rows 38disposed on the substrate 32 that are adjacent and parallel to eachother. As with the first rows 36, the second rows 38 resemble v-shapedrows and may have a 90° included angle. It also will be appreciated thatthe v-shaped rows may be arranged at angles less than or greater than90°, so long as the overall arrangement of the surface 34 does notreside in an overall same plane.

As shown, the second rows 38 are orthogonal to the first rows 36. Thus,four-sided pyramid-like structures 39 are formed by the 90° intersectionof first and second parallel rows 36, 38. It will be appreciated thatthe arrangement of the first rows 36 and the second rows 38 are notlimited to the specific orthogonal relationship shown, and that thefirst and second rows 36, 38 may intersect at angles other than 90°.

It further will be appreciated that an inlet face is not limited to thespecific arrangements shown in FIGS. 1-4. FIGS. 1-4 show exemplaryconfigurations only, where the inlet includes an end surface having athree-dimensional topographical configuration that may be, but is notlimited to, parallel V-shaped rows or two sets of intersecting v-shapedrows. It will be appreciated that the described end surfaces (i.e. 14,34) for an inlet face may be suitably modified and may have otherconfigurations, as long as the end surface can create exhaust flowturbulence and shear so as to minimize soot and/or exhaust materialadherence, can prevent and/or eliminate face-plugging.

As shown, the cellular structure (i.e. 15, 35) extends through an outersurface and at the end of the substrate (i.e. 12, 32). In one example ofan aftertreatment device, such as a flow-through DOC, the cellularstructure leads into channels that extend through the entire substratefrom the inlet side (where inlet face 10, 30 are disposed) to the outletside. It will be appreciated that the cellular structure may be employedin other aftertreatment devices, such as a DPF, that do not haveflow-through channels but includes an inlet face of a single channel atthe inlet side, and where a network of openings or pores lead intomultiple outlet channels to the outlet side.

The cellular structure defines separate cells that have inner sidewallsand wall edges (see FIGS. 1 and 3). The cells are configured such thatthey are adjacent of each other, and are disposed substantially aboutthe inlet face. As some examples only, an inlet face may include about100 to about 900 cells per square inch thereon.

In one embodiment, the inner sidewalls of each cell may include a firstpair of parallel walls and a second pair of parallel walls orthogonal tothe first pair of parallel walls. It will be appreciated the orthogonalconfiguration of the first pair of parallel walls with the second pairof parallel walls is merely exemplary, as the relationship between thefirst and second pair of parallel walls may be arranged such that theynot orthogonal or perpendicular to each other.

FIG. 5 further illustrates an exemplary cellular structure for an inletface. FIG. 5 shows a partial cellular structure and particularlydepicting a single cell 50, such as when a three-dimensionaltopographical surface is present. It will be appreciated that theprinciple shown in FIG. 5 may applicable to any of the inlet facesdescribed herein that have multiple cells in their cellular structures.Each cell 50 includes a first pair of parallel walls 53 and a secondpair of parallel walls 54. For example, the v-shaped rows orpyramid-like shapes of an inlet face (i.e. 10, 30) can produce an endsurface which has a significantly increased cell dimension at the end ofthe substrate, and that effectively serves to increase the distancebetween at least one of the two pairs of parallel walls 52, 54 for eachcell 50 at the inlet face. Thus, the distance required for fouling (i.e.carbonaceous fouling) to be bridged is increased, because the distancebetween the outer ends of at least one of the pairs of parallel walls isincreased.

As shown, the cell 50 has one pair of sidewalls 52, 54 orthogonal tosidewall 56. The sidewall 54 has a larger dimension than sidewall 52, soas to create an increased cell dimension “c,” such as at a 45° angle,versus a conventional cell configuration of an inlet substrate havingeven sidewalls with a planar dimension “a” (shown in dashed line). As anexample, by the Pythagorean Theorem, the dimension “c” will beapproximately 41% longer than the dimension “a” at a 45° angle. It willbe appreciated that the increased cell dimension is not limited to the45° angle shown, and may include an angle of higher or lesser degree, solong as the increased cell dimension is created in one of the walls ofone pair of parallel walls.

Thus, applying the principle illustrated in FIG. 5, at least one of thefirst or second pairs of parallel walls includes a first wall and asecond wall (i.e. 52, 54), where one of the first or second walls has alarger dimension, and extending further outwardly from the end of thesubstrate, than the other of the first or second wall. In thisconfiguration, the distance between the outer ends of the first andsecond walls of one pair of the parallel walls is larger than a distancebetween the first and second walls of the other pair of parallel walls.

FIGS. 6-17 illustrate other examples of three-dimensional topographicalconfigurations for an inlet face. FIGS. 6-7 show an inlet face 60 havingan end surface 64 disposed on a substrate 62 at the inlet side of anaftertreatment device, such as a DOC. The end surface 64 is outwardlybossed and resembles a convex “cupped” type 66 flow-throughaftertreatment device. As with the inlet faces 10, 30, the inlet face 60does not reside in the same plane. Rather, the end surface 64 isnon-planar or has a somewhat fractured arrangement. That is, the endsurface 64 does not reside entirely in the same overall plane, such aswhen viewed from its profile. (See for example FIG. 7.) The inlet face60 also includes a cellular structure 65 with multiple cells. As withthe cellular structures 15, 35 of inlet faces 10, 30, it will beappreciated that the cellular structure 65 of inlet face 60 mayincorporate increased cell dimension principles as described above inFIG. 5. It further will be appreciated that the inlet face 60 may beemployed in various aftertreatment devices other than a DOC.

FIGS. 8-9 show an inlet face 70 having an end surface 74 disposed on asubstrate 72 at the inlet side of an aftertreatment device, such as aDOC. The end surface 74 extends outwardly and resembles a convexparabolic type flow-through 76 aftertreatment device. As with the otherinlet faces described, the inlet face 70 does not reside in the sameplane. Rather, the end surface 74 is non-planar and has a somewhatfractured arrangement. That is, the end surface 74 does not resideentirely in the same overall plane, such as when viewed from itsprofile. (See for example FIG. 9.) The inlet face 70 also includes acellular structure 75 with multiple cells. As with the other cellularstructures described, it will be appreciated the cellular structure 75of inlet face 70 may also incorporate increased cell dimensionprinciples as described above in FIG. 5. It further will be appreciatedthat the inlet face 70 may be employed in various aftertreatment devicesother than a DOC.

FIGS. 10-11 show an inlet face 80 having an end surface 84 disposed on asubstrate 82 at the inlet side of an aftertreatment device, such as aDOC. The end surface 84 extends outwardly and resembles a convex roundedtype flow-through 86 aftertreatment device. As with the other inletfaces described, the inlet face 80 does not reside in the same plane.Rather, the end surface 84 is non-planar and has a somewhat fracturedarrangement. That is, the end surface 84 does not reside entirely in thesame overall plane, such as when viewed from its profile. (See forexample FIG. 11.) The inlet face 80 also includes a cellular structure85 with multiple cells. As with the other cellular structures described,it will be appreciated the cellular structure 85 of inlet face 80 mayalso incorporate increased cell dimension principles as described. Itfurther will be appreciated that the inlet face 80 may be employed invarious aftertreatment devices other than a DOC.

FIGS. 12-13 show an inlet face 90 having an end surface 94 disposed on asubstrate 92 at the inlet side of aftertreatment device, such as a DOC.The end surface 94 extends inwardly and resembles a concave depressed or“cupped” type flow-through 96 aftertreatment device. As with the otherinlet faces described, the inlet face 90 does not reside in the sameplane. Rather, the end surface 94 is non-planar and has a somewhatfractured arrangement. That is, the end surface 94 does not resideentirely in the same overall plane, such as when viewed from itsprofile. (See for example FIG. 13.) The inlet face 90 also includes acellular structure 95 with multiple cells. As with the other cellularstructures described, it will be appreciated the cellular structure 95of inlet face 90 may also incorporate increased cell dimensionprinciples as described. It further will be appreciated that the inletface 90 may be employed in various aftertreatment devices other than aDOC.

FIGS. 14-15 show an inlet face 100 having an end surface 104 disposed ona substrate 102 at the inlet side of an aftertreatment device, such as aDOC. The end surface 104 extends inwardly and resembles a concaveparabolic type flow-through 106 aftertreatment device. As with the otherinlet faces described, the inlet face 100 does not reside in the sameplane. Rather, the end surface 104 is non-planar and has a somewhatfractured arrangement. That is, the end surface 104 does not resideentirely in the same overall plane, such as when viewed from itsprofile. (See for example FIG. 15.) The inlet face 100 also includes acellular structure 105 with multiple cells. As with the other cellularstructures described, it will be appreciated the cellular structure 105of inlet face 100 may also incorporate increased cell dimensionprinciples as described. It further will be appreciated that the inletface 100 may be employed in various aftertreatment devices other than aDOC.

FIGS. 16-17 show an inlet face 110 having an end surface 114 disposed ona substrate 112 at the inlet side of an aftertreatment device, such as aDOC. The end surface 114 extends inwardly and resembles a concaverounded type flow-through 116 aftertreatment device. As with the otherinlet faces described, the inlet face 110 does not reside in the sameplane. Rather, the end surface 114 is non-planar and has a somewhatfractured arrangement. That is, the end surface 114 does not resideentirely in the same overall plane, such as when viewed from itsprofile. (See for example FIG. 17.) The inlet face 110 also includes acellular structure 115 with multiple cells. As with the other cellularstructures described, it will be appreciated the cellular structure 115of inlet face 110 may also incorporate increased cell dimensionprinciples as described. It further will be appreciated that the inletface 110 may be employed in various aftertreatment devices other than aDOC.

As some examples only, any of the three-dimensional topographicalconfigurations may be disposed on the inlet side or end of a substrateby any one of the following of: (1) applying a surface having thedesired three-dimensional topographical configuration on the substrateof the inlet; (2) machining the desired three-dimensional topographicalconfiguration into the substrate of the inlet; or (3) forming thethree-dimensional topographical configuration by any suitable means soas to dispose it onto the substrate. It will be appreciated that themanner in which the three-dimensional topographical surface is disposedon the inlet side of a substrate is non-limiting, as long as the surfacecan be put at the inlet side and at the end of the substrate.

The three-dimensional topographical surface structure of the inletsdescribed herein can provide many benefits. In operation, such surfacescan produce a degree of turbulent flow at the inlet face and a shearforce that would serve to help dislodge or prevent soot deposits. Thesurfaces described, for example in FIGS. 1-4 and 6-11, also can providefor faster heating on localized regions (i.e. the upper, sharp ridges ofthe V-shaped rows, the tips or pinnacles of the pyramids, or the raisedsurface portions in the convex configurations) of the inlet surface dueto a effective reduction of thermal mass in the fractured surfacestructure, thus assisting light off of any catalytic coating that mightapplied at the inlet face (described below) of an aftertreatment deviceand likewise any catalytic coating that is applied to the interior of anaftertreatment device.

As another particular benefit, the convex configurations shown in FIGS.6-11 can further provide an inlet face with faster heating capability.Such configurations can facilitate preventing and/or eliminating largercarbonaceous fouling deposits from clogging the inlet face (i.e. sootdeposits), such as may be released from the inner surface of an exhaustdown pipe. For example, in turbo exhaust applications these larger sootdeposits or “flakes” may break or crack off the inner surface of anexhaust down pipe after a critical thickness has accumulated (i.e. abouta millimeter thickness). These flakes can deposit on the inlet facethereby causing cells in the cellular structure to be bridged with soot.However, such convex configurations as FIGS. 6-1 1 can further preventthis bridging.

Coating of an Inlet Face

In yet another embodiment, an inlet face includes an end surface, whichis configured to prevent and/or eliminate face-plugging on thesubstrate. The end surface is provided with a chemical coating appliedto an outer surface at the end of the substrate and including outer endportions of the substrate's cellular structure. As one example only, thechemical coating is useful for an inlet face of an aftertreatment devicein reducing carbonaceous fouling, or more generally fouling, on theinlet face of the substrate. As with the three-dimensional topographicalconfigurations described, it will be appreciated that the appliedchemical coating may be suitably employed in various aftertreatmentdevices such as, but not limited to, a close-coupled catalyst (CCC), adiesel oxidation catalyst (DOC), a NO_(x) adsorber catalyst (NAC), aselective catalytic reduction (SCR) catalyst, a catalyzed soot filter(CSF), or a diesel particulate filter (DPF).

The chemical coating may be at least one of a ceramic washcoat or aglass-based coating, or chemical solution, or other carrier suitable forapplying the chemical coating. In one embodiment, such a chemicalcoating includes a material that is at least one selected from the groupconsisting of a catalytic precious metal, a catalytic precious metaloxide, a non-catalytic precious metal, a catalytic base metal, and acatalytic base metal oxide. In one embodiment, the chemical coating isan elevated loading at the inlet side and at the end of the substrate,for example an aftertreatment device. That is, the meaning of elevatedloading is that the inlet face (or end) of the substrate (i.e.aftertreatment device) includes an increased amount of chemical coatingat the end of the substrate than an amount of chemical coating that maybe employed within the fluid passageways (channels) inside aaftertreatment device.

For example, the application of a chemical coating contains an elevatedloading of catalytic precious metals (such as platinum (Pt) or palladium(Pd)), or base metals (such as vanadium (V)), or base metal oxides (suchas vanadium pentoxide or cerium oxide), or other compounds (such asbarium carbonate BaCO₃).

As one example only, the elevated loading can be in the range of about80-120 g/ft̂3. It will be appreciated that the amount of an elevatedloading is meant to be non-limiting and may include various amounts assuitable and/or necessary to achieve the desired effect of preventingand/or eliminating face-plugging.

As a further example, a glass-based coating is applied to the inletface, and may also contain an elevated loading of catalytic preciousmetals (such as platinum (Pt) or palladium (Pd)), or base metals (suchas vanadium (V)), or base metal oxides (such as vanadium pentoxide orcerium oxide), or other compounds (such as barium carbonate BaCO₃). Inone embodiment, the glass-based coating also contains potassium K. Insuch a configuration, the catalytic activity of the coating can help toprevent and/or eliminate soot deposits on an inlet face of anaftertreatment device. Additionally, an advantage may arise in which theglass coating can easily applied to the inlet face, and may provide forbetter filling-in or obstruction of microscopic pores and otherasperities on the outer exposed portions of wall edges of the cells.

As noted, the meaning of elevated loading is that the coating isdirectly and deliberately applied at the inlet surface. An elevatedloading is an increased amount of chemical coating disposed at the inletsurface or end of the substrate relative to an amount which may be usedinside and beyond the inlet face. That is, the chemical coating may beapplied as an extension of any coating present inside and beyond theinlet face. In the example of an aftertreatment device, the elevatedloading includes an increased amount of chemical coating at the inletface, which is more than what is typically employed within the channelsthroughout a catalyzed aftertreatment device.

Application of the chemical coating can include, for example, the freewalls and edges of the cellular structure at the outer surface of theinlet and at the end of the substrate. In one embodiment, the chemicalcoating is directly and deliberately applied on the inlet face on theouter end surfaces of the cellular structure of the substrate. That is,the chemical coating can act as an extension of any coating that may beapplied inside the fluid passageways of the substrate, and beyond theinlet face and end of the substrate. It further will be appreciated thatthe disposition of the chemical coating is not limited, so long as thechemical coating is applied to the inlet face.

It will be appreciated that in some cases, the chemical coatingintentionally applied to the inlet face or end of the substrate may alsounintentionally and incidentally be coated inside the fluid passageways.However, it will be appreciated that in the case of inlet face coatingthe chemical coating is intentionally applied at the end of thesubstrate on the outer end surfaces of the cellular structure, and isnot intended to be applied within the fluid passageways of thesubstrate.

As another alternative, the coating may be applied to fill in any roughsurfaces or asperities of the wall edges of a cell, and the coatingwould not extend into the flow passages of the substrate. In such aconfiguration, the surface area of the wall edges coated can furtherprevent carbonaceous fouling, such as the mechanical adhesion ofsoot/coke, by providing a surface that is less rough (or more smooth) asa result of the applied coating. As one example only, the coating may beapplied at a thickness of about no more than a few thousandths of aninch to achieve such minimized cell surface asperities.

FIG. 20 illustrates a schematic side sectional view of one embodimentfor the disposition of a chemical coating 404 on an inlet face 400. Asshown, application of the chemical coating 404 is applied on the outsidesurface of the cellular structure 402 on the inlet face. That is, thecoating 404 is applied such that it is a covering the outer surface atthe end of the substrate, which does not extend into the interior of thecells or channels of the substrate. The coating 404 would be applied toonly the wall and edge surfaces 402 of the inlet face 400 that faceoutward. As shown, the coating 404 is applied to a planar configurationof the end of the substrate. It will be appreciated that such a coatingconfiguration can be combined with any of the three-dimensionaltopographical configurations discussed in FIGS. 1-17, as long as thecoating is disposed on the outer surface as a covering on any threedimensional topographical configuration employed.

FIG. 21 illustrates a schematic perspective plan view for thedisposition of a chemical coating 504 on an inlet face 500. As shown,application of the chemical coating 504 is applied on the outsidesurface of the cellular structure 502 and on the inlet face. As in FIG.20, the coating 504 is applied such that it covers the outer surface atthe end of the substrate, and which does not extend into the interior ofthe cells or channels 506 of the substrate. The coating 504 would beapplied to only the wall and edge surfaces of the cellular structure 502that face outward from the end of the substrate. As shown, the coating504 is applied to a planar configuration of the end of the substrate. Itwill be appreciated that such a coating configuration can be combinedwith any of the three-dimensional topographical configurations discussedin FIGS. 1-17, as long as the coating is disposed on the outer surfaceas a covering on any three dimensional topographical configurationemployed. In FIG. 21, the coating 504 is illustrated as not covering theentire end surface of the cellular structure 502 for purposes of showingthe disposition of the coating on the end of the substrate. However, itwill be appreciated that the coating 504 would substantially cover theend of the substrate.

It will be appreciated that the coating is not limited to a specificformulation, as long as the coating is formulated to preventcarbonaceous fouling at the exposed edges of the cellular structure atthe inlet face. That is, it will be appreciated that the chemicalcoating may be formulated to further a selective catalyst reaction, soas to further the function of preventing, eliminating and/or reducinginlet face-plugging.

As with the three-dimensional surface configuration, the coatingsdescribed can eliminate the need to build separate mechanisms forface-plugging detection and cleaning into the controls of an exhaustaftertreatment system.

As another example only, multiple NO to NO₂ turns (NO_(x) turns) at theinlet face can advantageously result due to the elevated loading of thechemical coating, and can be further enhanced as a result of employingany of the three-dimensional topography configurations discussed above.That is, the resulting coating and turbulent flow can enhance the NO₂driven oxidation of hydrocarbon and/or soot, presented to or depositedon the inlet face. Below is one illustration of the reaction mechanismin the presence of the precious metal catalyst, platinum Pt.

In one embodiment, the multiple NO_(x) turn reactions can occur in theexhaust stream of a diesel engine that employs the described inlet facecoating on an inlet of an aftertreatment device. The reaction over acatalyst (e.g. Pt) of NO with excess oxygen to produce NO₂ is:

NO+½O₂→NO₂   1)

This NO₂ is subsequently used to oxidize carbon soot accumulated on theinlet face of the aftertreatment device through the following reactions:

For carbon soot:

2NO₂+C→CO₂+2NO   2)

NO₂+C→CO+NO   3)

The NO created by reactions (2) and/or (3) can again be oxidized at theinlet face of the aftertreatment device to form NO₂ via reaction (1)which will then proceed through reactions 2 and 3 repetitively until thecarbon soot is consumed. This is called a “NO_(x) turn.”

For unburned hydrocarbon (HC) adsorbed on the soot, it is consideredthat the following catalyzed reactions (4) and (5) may also occur,essentially producing a drier soot accumulation that does not easilystick to the inlet face of the aftertreatment device. Furthermore, thethermal energy created by burning the HC on the additional catalyst (orelevated loading of catalyst) at the inlet face will help oxidize (i.e.burn) the accumulated soot.

C_(y)H_(n)+(1+n/4)O₂ →yCO₂ +n/2H₂O   4)

CO+½O₂→CO₂

In the above examples, reactions (1), (4) and (5) are catalyzed by acatalyst such as Pt. It will be appreciated, however, that while thereactions and resulting products may be somewhat different for catalystsother than Pt, the same principles apply in using a suitably formulatedcoating to react with the exhaust materials and thereby preventcoking/adhesion of soot at the inlet face.

As with the three-dimensional topographical surface configurationsdescribed above, any of the described coating embodiments may be appliedto the cellular structures already described and at the inlet face of asubstrate. FIGS. 18-19 illustrate separate embodiments of cellularstructures for an inlet face. In one embodiment, a cellular structure200 is configured such that the cells 202 are adjacent each other, andwould be disposed substantially about an inlet face. The cellularstructure 200 has some similarity with the illustrations of FIGS. 1-4and 6-17. As described, inlet surface 200 may include about 100 to about900 cells per square inch on the inlet face. The sidewalls 204 of eachcell 202 may include a first pair of parallel walls and a second pair ofparallel walls orthogonal to the first pair of parallel walls.

FIG. 19 illustrates a cellular structure 300 in which portions of thecellular structure 300 are plugged. As shown, the cellular structure 300includes cells 302 and plugged portions 304 arranged in a “checker-boardlike” configuration, such that portions other than sidewalls (i.e.sidewalls 204 of cellular structure 200) of the cellular structure areblocked. It will be appreciated that the cellular structures 200, 300are merely exemplary and are not limited to the specific configurationsshown, as long as the cellular structure can incorporate any of thethree-dimensional topographical surface configurations and/or any of thechemical coating embodiments described.

Experimental Results

Some of the above have been tested in a modified DOC on an engine andshowed favorable results with additional Pt catalyst applied to theinlet face. After several test cycles on the engine, the inletface-catalyzed DOC did not plug with soot. Also, the describedtopographical modifications to the inlet face appeared to have apositive effect under some engine operating conditions, by creatingturbulence and localized heating on the inlet.

However, a standard DOC, which had no additional catalyst on the inletface or a modified topographical configuration, was significantly faceplugged with soot.

It will be appreciated, however, that the reactions and resultingproducts may be somewhat different for catalysts used other than Pt.

Other experiments have been conducted at the Cummins Technical Center,in which ultra low sulfur diesel (ULSD) fuel was dripped on an inletcomposed of 420F stainless steel disks coated with vanadium metal at atemperature of approximately 220° C.. The experiments showed that theresulting carbon deposits do not adhere to the vanadium surface.

Another experiment using a platinum metal rather than a vanadium metalsurface yielded identical results. It is expected that a ceramicwashcoat which is highly loaded with precious metals such as a Pt and/orPd oxide would exhibit similar results. In yet another example, aceramic washcoat containing cerium oxide may also be employed undercertain temperature conditions. In still another example, it would beappreciated that an SCR-like catalyst washcoat, such as one containingvanadium pentoxide, iron zeolite or copper zeolite, also may be used andcan produce a similar effect.

The inlet structure described can provide many benefits. By employing anon-planar, three-dimensional topographical configuration and/orchemically modified inlet face, face-plugging can be prevented and/oreliminated. In one preferred example, such a structure is useful forpreventing the deposition of soot on the inlet face of an aftertreatmentdevice, such that the soot does not bridge and thus plug normally openchannels through which exhaust gases flow under typicalengine/aftertreatment system operating conditions.

Such a beneficial inlet face structure may be useful in variousapplications. As some non-limiting examples only, the inlet facestructure may be employed in the exhaust stream of vehicular orautomotive engines, diesel engines, marine engines and equipment,industrial power generators, equipment used in industrial processes, orany other equipment that employ aftertreatment devices or that use fuelsgenerating coking material.

The invention may be embodied in other forms without departing from thespirit or novel characteristics thereof. The embodiments disclosed inthis application are to be considered in all respects as illustrativeand not limiting. The scope of the invention is indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are intended to be embraced therein.

1. An inlet face for a fluid passageway comprising: a substrateincluding an end having a cellular structure configured to enable fluidflow through the substrate, and an end surface disposed on the end ofthe substrate and on outer surfaces of the cellular structure located atthe end of the substrate, the end surface configured to prevent and/oreliminate face-plugging on the substrate.
 2. The inlet face of claim 1,wherein the end surface disposed on the end of the substrate comprisesat least one of a three-dimensional topographical configuration suchthat the substrate is non-planar at the end, a chemical coating disposedon the end of the substrate, or both a three-dimensional topographicalconfiguration disposed on the end of the substrate and a chemicalcoating disposed on the three-dimensional topographical configuration.3. The inlet face of claim 2, wherein the three-dimensionaltopographical configuration comprises a plurality of adjacent v-shapedparallel rows.
 4. The inlet face of claim 2, wherein thethree-dimensional topographical configuration comprises a firstplurality of adjacent v-shaped parallel rows and a second plurality ofadjacent v-shaped parallel rows that are orthogonal to the firstplurality of adjacent v-shaped rows, such that the first and secondplurality of adjacent v-shaped rows are configured as a multiplefour-sided pyramid-like arrangement.
 5. The inlet face of claim 2,wherein the three-dimensional topographical configuration is appliedonto the end of the substrate or is machined into the end of thesubstrate.
 6. The inlet face of claim 2, wherein the chemical coating isat least one of a ceramic washcoat, a glass-based coating, or a chemicalsolution, such that the chemical coating is at least one selected fromthe group consisting of a catalytic precious metal, a catalytic preciousmetal oxide, a non-catalytic precious metal, a catalytic base metal, anda catalytic base metal oxide.
 7. The inlet face of claim 6, wherein thechemical coating is an elevated loading relative to any other coating onthe substrate, where the elevated loading is present at only the end ofthe substrate.
 8. The inlet face of claim 1, wherein the cellularstructure comprises a plurality of separate cells extending into the endof the substrate and through the substrate, the cells each havingsidewalls and wall edges.
 9. The inlet face of claim 8, wherein thecells are configured adjacently of each other and are disposedsubstantially about the entire area of the end surface.
 10. The inletface of claim 8, wherein the cellular structure comprising a pluralityof plug portions arranged with the plurality of cells.
 11. The inletface of claim 8, wherein the sidewalls of each cell comprise a firstpair of parallel walls and a second pair of parallel walls orthogonal tothe first pair of parallel walls, one of the first or second pairs ofparallel walls comprises a first wall and a second wall, one of thefirst or second walls having a larger dimension extending outwardly fromthe end of the substrate than the other of the first or second wall,such that the distance between outer ends of the first and second wallsis larger than a distance between outer ends of the other of the firstor second pair of parallel walls.
 12. The inlet face of claim 1, whereinthe substrate and the end surface are configured as an inlet componentfor an aftertreatment device, the aftertreatment device selected from atleast one of the group consisting of a close-coupled catalyst, a dieseloxidation catalyst, an NO_(x) adsorber catalyst, a selective catalyticreduction catalyst, a catalyzed soot filter, or a diesel particulatefilter.
 13. An aftertreatment device comprising: a substrate includingan end having a cellular structure configured to enable fluid flowthrough the substrate, the cellular structure being an inlet facedisposed at the end of the substrate, and an end surface disposed on theend of the substrate and on outer surfaces of the cellular structurelocated at the end of the substrate, the end surface configured toprevent and/or eliminate face-plugging on the substrate.
 14. Theaftertreatment device of claim 13, wherein the end surface disposed onthe substrate comprises at least one of a three-dimensionaltopographical configuration such that the substrate is non-planar at theend, a chemical coating disposed on the end of the substrate, or both athree-dimensional topographical configuration disposed on the end of thesubstrate and a chemical coating disposed on the three-dimensionaltopographical configuration.
 15. The aftertreatment device of claim 14,wherein the three-dimensional topographical configuration comprises aplurality of adjacent v-shaped parallel rows.
 16. The aftertreatmentdevice of claim 14, wherein the three-dimensional topographicalconfiguration comprises a first plurality of adjacent v-shaped parallelrows and a second plurality of adjacent v-shaped parallel rows that areorthogonal to the first plurality of adjacent v-shaped rows, such thatthe first and second plurality of adjacent v-shaped rows are configuredas a multiple four-sided pyramid-like arrangement.
 17. Theaftertreatment device of claim 14, wherein the three-dimensionaltopographical configuration is applied onto the end of the substrate oris machined into the end of the substrate.
 18. A method for preventingand/or eliminating face-plugging on an inlet of an aftertreatment devicecomprising: forming a substrate having an end with a cellular structurethat is configured to enable fluid flow through the substrate; disposingan end surface on the end of the substrate and on outer surfaces of thecellular structure located at the end of the substrate, the end surfaceis configured to prevent and/or eliminate face-plugging on the substrateand cellular structure.
 19. The method of claim 18, wherein disposingthe surface on the substrate further comprises at least one of:disposing a three-dimensional topographical configuration on the end ofthe substrate such that the substrate is non-planar at the end, applyinga chemical coating on the end of the substrate and on outer surfaces ofthe cellular structure present at the end of the substrate, or disposingthe three-dimensional topographical configuration on the end of thesubstrate and applying a chemical coating on the three-dimensionaltopographical configuration, such that the chemical coating facesoutward from the end of the substrate.